No, but you need air to dry it. The same goes with mud, really. The Octopuses might be able to graft coral and create grottoes that way, though.

What if the under-water species were able to produce buildings and other constructs naturally, without the use of fire? Perhaps the creature is capable of creating nests out of a resin, made from chewing up some kind of material (like bees and wasps making a nest). Then when the species reaches a level of intelligence, their nests become more elaborate. What if they had symbiotic relationship with other marine life for a mode of transportation? (like humans and horses) What if the creature itself is large like a whale, eventually evolving the ability to develop a hard outer shell, and naturally progressing to a space-faring state of development. Or could it be possible for them to grow ships, maybe even entirely organic space-faring vessels? We can't dismiss these possibilities just because we have no real-life examples to go on.

I've seen the argument against 'under-water intelligence being able to producing fire' at least twice on these forms now, but I think we can't get stuck on fire being the "be-all end-all" beginning of technology and development as we know it just because that's how we developed.

Or perhaps, they discover fire after being moderately intelligent for some time, and by first creating gas pockets in their habitats in which fire can exist and be harnessed. Or, the creature can cover itself with a reign "environmental suit" which contains it's aquatic habitat temporarily, enabling excursions to dry land where fire may be discovered and utilized (with their travel to land being like humans exploring the moon, simply another hurdle). Perhaps under-water life would take longer to develop technology than land faring organisms, simply because they have more hurdles to overcome, but that wouldn't stop them and I think it shouldn't take them out of Thrive.

My 2 cents

We've never said that they could not build a civilization, it's just that, essentially, their technology could not progress very far without the use of fire. Metallurgy is one of the key steps in progressing foreword, and it's impossible underwater. Certainly, large cities, farming, the wheel - these are all very possible for an aquatic civilization to develop, but they will never get to space without getting onto land for large periods of time, and thus becoming technologically amphibious.

I'd like to point something out out, it's three words: Underwater Volcanic Vents. Now I don't know what would happen IRL for an intelligent species in the open seas, but a recent thought experiment of mine based on Europa and "Europan life" if it exists got me wondering, if life would be suited to only thrive around volcanic vents, then these would be the centerpiece to their societies. They would replace fires that early humans used. Heating metal would be no problem for them if they found some just washing around, thus, casting and smithing might not be impossible, but it would be dangerous and difficult. I say that technological societies underwater are indeed possible, but only if the life is centered on underwater volcanic vents.

A (brief) check on wikipedia tells me:
Average hydrothermal vent temperature = below 500℃
Useful-for-metal-reactions fire temperature = above 1000℃ (to about 2000℃)

Also, apparently vents are cooler than the hottest part of cigarettes... Well, you don't see people using cigarettes for metalwork, so that sort of puts it in perspective.

Dang, thought I had something there. Oh well, guess underwater civs are doomed. =\

Shouldn't we leave an open variable in case the player is more creative then us? Just set the "Metal Working Ability" to be usable if the species can repeatedly create temps over 'x' degrees? (who knows how, but this seems more in the spirit of the game to me)

A civilization underwater, in my opinion, is at a disadvantage compared to civilizations like ours out of the water because we filter all according to our knowledges of our civilization ...

A civilization of sentient creatures underwater can create huge domes without water, connected by pipes to the outside to allow oxygen to enter, where they work in metals with special suits to allow them to live in the presence of oxygen ( a bit like our suits to go under the water but whose function in reverse).

What do you think?

P. S. sorry my bad english

[quote="Doggit"]A civilization underwater, in my opinion, is at a disadvantage compared to civilizations like ours out of the water because we filter all according to our knowledges of our civilization ...

QFT.
The hard part is deciding where our perception ends and reality begins. Domes seems possible, many organisms excrete gases that are at least somewhat flammable (see methane fires in swamps), so containing them isnt all that much of a stretch. Just gotta keep it open I say.

I would like to ask if it would be possible to uplift a underwater species when you had enough technology.

Say for example, you species evolved on a planet with little land and open oceans. Your race was comparable to pelicans and the main diet was fish. I think it would be interesting if it would be possible to uplift, say, a manatee like species to herd fish into one location. It would allow workers in the food section of an economy to work in other places.